/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.xml.security.samples.transforms;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;

import org.apache.xml.security.signature.XMLSignatureInput;
import org.apache.xml.security.samples.DSNamespaceContext;
import org.apache.xml.security.samples.SampleUtils;
import org.apache.xml.security.transforms.Transforms;
import org.apache.xml.security.utils.Constants;
import org.apache.xml.security.utils.XMLUtils;
import org.w3c.dom.Element;

/**
 * This class demonstrates the use of a Transform for XSLT. The
 * <CODE>xsl:stylesheet</CODE> is directly embedded in the <CODE>ds:Transform</CODE>,
 * so the {@link Transform} object is created by using the Element.
 *
 * @author Christian Geuer-Pollmann
 * @version %I%, %G%
 */
public class SampleTransformChaining {

    /**
     * Method main
     *
     * @param args
     * @throws Exception
     */
    public static void main(String args[]) throws Exception {
        String inputStr =
            "<?xml version=\"1.0\"?>" + "\n"
            + "<Class>" + "\n"
            + "   <BASE64>" + "\n"
            + "       PGNvbnRhaW5lcj4KICAgPGU+SGVsbG8sIDwhLS0gY29tbWVudCAtLT4gd29ybGQhPC9lPgogICA8" + "\n"
            + "       T3JkZXIgTmFtZT0nVElOQU1JRk9STUVTJyB4bWxucz0naHR0cDovL3NmZGZnLyc+CiAgICAgIDxG" + "\n"
            + "       YW1pbHkgTmFtZT0nVElOQU1JREFFJz4KICAgICAgICAgPFNwZWNpZXMgU2NpZW50aWZpY19OYW1l" + "\n"
            + "       PSdDcnlwdHVyZWxsdXMgYm91Y2FyZGknPlNsYXR5LWJyZWFzdGVkIFRpbmFtb3UuPC9TcGVjaWVz" + "\n"
            + "       PgogICAgICA8L0ZhbWlseT4KICAgPC9PcmRlcj4KICAgPE9yZGVyIE5hbWU9J1BPRElDSVBFRElG" + "\n"
            + "       T1JNRVMnLz4KPC9jb250YWluZXI+Cg==" + "\n"
            + "   </BASE64>" + "\n"
            + "<Signature Id='SignatureToBeOmitted' xmlns='http://www.w3.org/2000/09/xmldsig#'>" + "\n"
            + "     <SignedInfo>" + "\n"
            + "       <Reference URI=''>" + "\n"
            + "         <Transforms>" + "\n"
            + "           <Transform Algorithm='http://www.w3.org/TR/1999/REC-xpath-19991116'>\n"
            + "             <!-- Exclude all signatures -->\n"
            + "               <ds:XPath xmlns:ds='http://www.w3.org/2000/09/xmldsig#'>\n"
            + "                 ancestor::BASE64"
            + "               </ds:XPath>\n"
            + "           </Transform>\n"
            + "           <Transform Algorithm='http://www.w3.org/2000/09/xmldsig#base64' />\n"
            + "           <Transform Algorithm='http://www.w3.org/TR/1999/REC-xpath-19991116'>\n"
            + "               <ds:XPath xmlns:ds='http://www.w3.org/2000/09/xmldsig#'>\n"
            + "                 not(self::container)     "
            + "               </ds:XPath>\n"
            + "           </Transform>\n"
            + "           <Transform Algorithm='http://www.w3.org/TR/2001/REC-xml-c14n-20010315' />\n"
            + "         </Transforms>" + "\n"
            + "       </Reference>" + "\n"
            + "     </SignedInfo>" + "\n"
            + "   </Signature>"
            + "</Class>" + "\n"
            ;
        
        org.apache.xml.security.Init.init();
        javax.xml.parsers.DocumentBuilderFactory dbf =
            javax.xml.parsers.DocumentBuilderFactory.newInstance();

        dbf.setNamespaceAware(true);

        javax.xml.parsers.DocumentBuilder db = dbf.newDocumentBuilder();
        org.w3c.dom.Document doc =
            db.parse(new java.io.ByteArrayInputStream(inputStr.getBytes()));

        XPathFactory xpf = XPathFactory.newInstance();
        XPath xpath = xpf.newXPath();
        xpath.setNamespaceContext(new DSNamespaceContext());

        String expression = "//ds:Transforms[1]";
        Element transformsElement = 
            (Element) xpath.evaluate(expression, doc, XPathConstants.NODE);
        
        Transforms transforms = new Transforms(transformsElement, "memory://");
        XMLSignatureInput input = new XMLSignatureInput(doc);

        // execute Transforms
        XMLSignatureInput result = transforms.performTransforms(input);

        // output result
        System.out.println(new String(result.getBytes()));
    }
    
}